The RIDGID® Tri-Stack™ 5 Gallon Air Compressor is the most innovative 5 in 1 compressor on the market, it is also easy to use and comfortable to carry. The Tri-Stack™ has an innovative removable compressor design that can be use in five different configurations: Tanks separate for easy carrying, Tanks can be use together for maximum tank capacity, Tanks separated -- Main/carry tank for any small jobs, Tanks Separated -- Compressor with compact tank for a complete regulated system and Tanks Separated and connected with hose for the best regulated surge tank experience that ensures consistent pressure when using long hoses.